Mason,
I just spent this past weekend looking for filters for my Saratoga spa. It had pleatco filters, so I started shopping around. From Pleatco's website, they game me names of local vendors. Of course nobody had them in stock, but said they could order them for me. I think its a matter of preference between Pleatco and Filbur, of the people I spoke with they preferred one or the other. Nothing horrible with either, just a matter of preference much like Chevy vs. Ford, Pepsi vs. Coke, etc.
The key is getting the right size and most of the websites have a conversion where you type in your info and you get product numbers for all of the companies. I even found that price varied between all of our local vendors who said they could order them, as much as $20 difference for the pleatco brand.
I finally decided to buy online from HotTubworks.com I had purchased something else from them before and their filter look up guide gave me everything that I needed to know. They shipped today so I can give you more info in a few days.